R33 Steering Rack Solenoid

[89CAL]

Have a weird problem with my car at the moment, and everything I can find seems to have to do with HICAS, I dont think its the issue on my car

Anyway, car is an R33 GTS-t, put a HICAS lock bar in it probably 2 years ago, hadn't had an issue since I put it in. Just did the usual unplug the HICAS bulb to stop it. But anyway, car drove fine, steering normal etc

So late last year I pulled my engine out to change the engine, put the new engine back in, started having problems with Power steering being heavy every now and then. Then all of a sudden it was fine, worked good. Took the car to my tuner, was working on the way out, and then when I got it back the steering is heavy again. He told me the steering was heavy the whole time he was tuning it, so don't believe it was anything he has done.

Now the funny part. Everytime I drive the car first up, the steering works perfect, no matter how long I drive for. As soon as I turn the car off then go to drive it again, no power steering.

It has plenty of fluid, and the fact that the steering works fine on the first startup makes me think its not pump or fluid related. It looks like the solenoid in the rack that (as far as I know) changes the power steering assist depending on speed is having some sort of problem.

Does anyone have a better idea of how this system works? I had a quick look yesterday and the plug and wires seem alright. has anyone had this issue before?

[boostn0199]

What happens when you unplug the sensor?

[89CAL]

I'm actually just about to do that

Power steering worked fine today for the first 3 startups then back to nothing again. Strange.

I will unplug the solenoid and see what happens

Edited January 21, 2014 by 89CAL

[GTSBoy]

Perhaps look for a broken wire. I don't know what the wiring route is like in R33s, but once, waaaay back, in my R32 I had a faulty O2 sensor melt up the loom. One of the other wires in that loom was that PS solenoid, and so I got no PS. Was an interesting day of fault finding in the workshop when we did that one!

Anyway, on the basis of that weird experience, you could go looking for damage in the loom, as unlikely as it is.

[89CAL]

Yeah its a bit odd so something like that is a pretty likely to be the problem.

Unplugged the solenoid before and didnt change anything. I thought it might fail to full power steering assist but must go the other way.

Will try and look at the loom but I have it all wrapped in heat wrap so might be a bit of a pain lol.

GTSBoy: Do you have any more info on your problem? I've cut the plug for my 02 sensor out because I'm only running the wideband with the Link. Nothing looks to obvious around the plug (PS Rack), and its hard without a good wiring schematic of that part of the car. Can find plenty on the engine but none on that

I assume it runs to the HICAS computer, but without knowing what Pins it goes to I can't really do any continuity checks between the plug and HICAS computer

I'll have a general look around the wiring and see if I can find anything in the mean time

[GTSBoy]

Defo goes to the HICAS CU. One leg would be power, other leg earthed through HICAS being the most likely guess. Grab the R32 GTR workshop manual and look at the wiring in that. It won't be the same same because difference HICAS, but it should be conceptually the same. Wire colour should be same from one end to the other for example, allowing you to have best guess as to which terminal on the CU it is supposed to connect to.

In my case, the loom that carries the power to the heater in the O2 sensor got real hot and melted the loom on the exhaust side of the engine bay ( I think).

[sonicz]

Why don't you do the HICAS computer short circuit trick. It was just shorting 2 pins with a wire in the Boot. No need to remove the bulb either and it solved all the HICAS issues from memory.

I can look it up for you if you don't know what I'm referring to.

[89CAL]

Yeah but then you get full power steering all the time. I dont like light steering at high speed.

Will look more when im home from work at it anyway. Have some wiring diagrams now so can check for faults between front and rear

[turboedsloth]

How did you go with this problem?

[89CAL]

Still appears every so often. Only seems to happen when the car gets hot but is still pretty hard to predict. Think ill just have to meter the circuit and see if there is a wiring issue. But like I said it was never an issue before the engine swap.

Have pulled the HICAS ecu out to have a look at the pins and plugs but it all looks brand new

[turboedsloth]

I pulled this hicas ecu out the other day and found some fried capacitors. Booked in for the auto sparky on tues

[89CAL]

were you having similar issues?

[89CAL]

Small update. I put a meter on the plug to the solenoid the other day (from the HICAS ECU) when the issue happened and It was getting 12v, so the issue must be with the solenoid or the wiring. I'm going to test reistance accross the coil when I have something I can hook onto the pins. I'm using someone elses multimeter so I dont have my aligator clips

Hopefully its a wiring issue or something. Otherwise I will just buy a new solenoid section of the rack

[GTSBoy]

Um....is/should be always 12V there and earth switched?

[89CAL]

yeah but it was 12V accross the plug so to get 12v it has to be earthed

If it wasnt earthed it would not show correct voltage AFAIK

[flano87]

I'm having the same problem .... when I turn the car off mid-journey to get petrol when I start the car back up again there is little to no power steering I think it is working but very inefficiently because its heavy ... it seems to lighten up at higher speeds ? reverse of what it should be doing......

[89CAL]

It probably doesnt change the effort at all, but beacuse less effort is needed when going fast it will feel alot lighter. Mine is the same, it feels normal at higher speed but heavy at low speed because The solenoid is doing nothing

mine is related to time with the key off AFAIK. 10 mins or so key off and then it wont work when its turned back on, leave it for half an hour or more and its fine.

I Don't think its related to the solenoid because if its working, I can sit there for ages and it doesnt die, I can drive for ages and it doesnt die. It just wont work again when I key off for a little bit then back on. I'm thinking about putting a relay in the battery power supply to the HICAS CU to make it reset everytime the ignition is turned on. Not sure if its going to work but worth a try.

[flano87]

sounds like a good idea, let me know how it goes!

[turboedsloth]

Narrowed my problem down to a couple of blown capacitors in the hicas ecu. Dont know what caused it but has been working fine for a while now

[GTSBoy]

I pulled this hicas ecu out the other day and found some fried capacitors. Booked in for the auto sparky on tues

Narrowed my problem down to a couple of blown capacitors in the hicas ecu. Dont know what caused it but has been working fine for a while now

I've posted about this before. There are two possible problems here. 1) Simply old electronics with late 80s/early 90s manufactured electrolytic capacitors finally having reached the end of their life expectancy. Changing them out before before other components in the CU get damaged is the only real hope. 2) There was a factory service bulletin in the Australian R32 GTR service manual to the effect that R32 HICAS CUs were reported to have a problem with a screw coming loose inside and drifting around, causing shorts and other problems. Service personnel were to open all such CUs and locktite the screws. Obviously this would not have happened to any grey import GTRs or GTSts.

It's good that you found faulty caps and that replacing them has helped. Just make sure you used good quality replacements, not cheap Jaycar Chinese ones. I have replaced so many caps in things like my washing machine and amplifiers only to have them die again 2 years later. Replace them again with better caps and they keep going for years.